Switch for electronic musical instruments



June 25, 1963 H. E. HOLMAN SWITCH FOR ELECTRONIC MUSICAL INSTRUMENTS 2Sheets-Sheet 1 Filed Oct. 8, 1959 June 25, 1963 H. E. HOLMAN 4 3,095,465

SWITCH FOR ELECTRONIC MUSICAL INSTRUMENTS Fiied Oct. 8, 1959 2Sheets-Sheet 2 IN V EN TOR.

gmardjiyolrm United States Patent Ohio Filed Oct. 8, 1959, Ser. No.845,117 8 Claims. (Cl. 84--1.01)

This invention relates generally to electrical switches and especiallyto switches for electronic musical instruments.

Switches for electronic musical instruments and the like commonlycomprise complex arrangements of intricately shaped parts which requireinsulating guide assemblies in order to prevent accidental shorting.Switches so comprised rare difiicult to assemble and expensive tomanufacture. Therefore, an important object of the present invention isto provide an improved switch for electronic musical instruments whichis simply constructed and which is economical to manufacture.

Another object of the invention is to provide a switch arrangement ofthe type described which is characterized by a minimum number ofoperating parts.

Still another object of the invention is to provide a switch arrangementfor electronic musical instruments which obviates the need for complexinsulating guide assemblies.

Additional objects and features of the invention pertain to theparticular structure and arrangements whereby the above objects areattained.

In order that the principle of the invention may be readily understood,a single embodiment thereof applied to an electronic organ, but to whichthe application is not to be restricted, is shown in the accompanyingdrawings wherein:

FIG. 1 is a perspective view of an electronic organ key associated witha switch arrangement in accordance with the present invention;

FIG. 2 is a fragmentary plan view of a multiplicity of organ keys eachbeing associated with a switch arrangement in accordance with theshowing of FIG. 1;

FIG. 3 is an elevational side view in partial crosssection of theshowing of FIG. 1, illustrating the switch in its normal or restposition; and

FIG. 4 is an elevational side view in partial crosssection of theshowing of FIG. 1 illustrating the switch in its operating position.

Referring now in detail to the drawings, specifically to FIG. 1, anorgan key is shown pivotal-1y mounted to a balance rail 12 by meansincluding a balance rail pin 14 in accordance with customary practice.The balance rail 12 is integrally joined to a keybed 16 which extendsacross the body of an electronic organ to support the multiplicity ofkeys normally provided.

Rearwardly of balance rail pin 14, a rigid switch arm 18 is secured tothe key 10 by means of a fastening screw 20. Switch arm 18 extends anend portion 22 to overhang the rear end of key 10, an electricallyinsulating tab 24 being aifixed to end portion 22 by a rivet or othersuitable means. A tension spring 26 advantageously extends between thetab 24 and a bracket 28 secured to the keybed 16. Spring 26 serves tobias the keyboard end of organ key 10 in a vertically upward direction.

Tab 24 is further adapted to serve as a contact pusher; and accordingly,a whisker wire contact 30 is suitably secured to a circuit board 32 toextend toward key 10 and to reside in a slot provided in the tab 24,board 32 acting as a structure means for supporting the contact 30.Contact 30 is preferably associated with the signal input 3,095,465Patented June 25, 1963 circuit which incorporates the continuouslyoperating oscillators customarily incorporated in an electronic organ.

Circuit board 32 is spaced rearwardly apart from key 10 in order toextend a pair of generally L-shaped, fixed contact elements 34 and 36 inthe direction of tab 24. Fixed contact elements 34 and 36 are adapted tosandwich contact element 30 between their free ends; and since contactelement 30 is arranged to make connection with contact element 36 in thenormal or rest position, contact element 36 is preferably associatedwith ground. Contact element 34 is consequently associated with thesignal output circuit which is printed or otherwise suitably applied toboard 32.

Board 32 extends across the body of the organ to support and makesuitable connections with the contact elements associated with each ofthe organ keys, as is best shown in FIG. 2.

While the striking of the musical note is achieved through contactelements 30, 34 and 36, it is sometimes desirable to actuatesimultaneously the percussion effects of the organ notes. Accordingly,switch arm 18 includes an upwardly canted, forwardly extending endportion 38 having an electrically insulating tab 48 secured thereto asby rivets or other suitable means.

Disposed across the body of the organ above tab 40 is a channel element42. Channel element 42 supports a percussion circuit board 44 from whicha pair of electrical conductors 46 and 48 depend in vertically aligned,parallel relationship. Conductors 46 and 48 are mounted to the circuitboard 44 by means of a number of electrically insulating brackets '50spaced at intervals along the board 44. Furthermore, conductors 46 and48 are preferably associated respectively with the percussion circuitand with power.

In order to provide selective operation of the percussion circuit, amoveable contact element 52 extends an end portion 54 between theconductors 46 and 48 and depends an oflfset mid-portion 55 adjacent thetab 40. Contact element 52 is secured to circuit board 44 by a mountingpost 56. Advantageously, a resistor 58 is electrically connected inseries between contact element 52 and a capacitor 60.

So that the musical note circuit associated with circuit board 32 may beactuated slightly ahead of the percussion circuit associated withcircuit board 44, the positions of end portions 22 and 38 are arrangedto be adjusted by means of the adjusting screws 62 and 64 respectively.

It has been found that the illustrated arrangement of conductors 46 and48 and of contacts 30, 34, 36 and 52 produces a switch which exhibitslittle or no tendency to develop accidental short circuits.Consequently, the need for insulating assemblies guiding the severalcontacts is precluded.

For purposes of providing an easy understanding of the invention, it isadvantageous to provide at this juncture a functional description of themode in which the component parts thus far identified cooperate. Turningtherefore to FIG. 3 in which the rest or normal configuration isillustrated, it will become apparent that the moveable contact element30 norm-ally makes connection with the grounded fixed contact element36. Also, in this normal or rest position, moveable contact element 52normally has its end portion 54 disposed in electrical connection withthe power input conductor 48. With the percussion switch on the normaldisposition of contact element 52 permits capacitor 60 to be chargedthrough resistor 58.

With particular reference now to FIG. 4, it will become apparent that,when organ key 10 is depressed in the general direction indicated byarrow 66, the signal input of the musical note circuit will be connectedto the signal output by means of moveable contact 30 being repositionedinto electrical connection with fixed contact 34. Simultaneously, thepivotal movement of key will cause tab 40 to encounter mid-portion 55urging contact 52 upwardly so that the end portion 54 makes connectionwith the percussion output conductor 46. Contact 52 being so disposed,capacitor 60 will discharge through resistor 58 so as to controlamplifier conduction effectuating the appropriate percussion.

It will be realized that release of organ key 10 will allow the biasingspring 26 to return the key 10 to its rest position. Once again moveablecontact 30 will be connected to grounded fixed contact 36; and contactelement 52 will be connected with the power input conductor 48 wherebycapacitor 69 will be restored for charging.

As will become apparent, a switch such as has been hereinabovedescribed, is advantageously associated with each of the organ keysdisplayed in the keyboard. FIG. 2 shows a portion of such a multiplearrangement; and insofar as duplicate elements have been illustrated,like numerals have been used to denote like elements, the suffix lettersa, b, etc. being applied to the duplicate members.

While a particular embodiment of the invention has been shown, it willbe understood, of course, that the invention is not limited theretosince many modifications may be made; and it is, therefore, contemplatedto cover by the appended claims any such modifications as fall Withinthe true spirit and scope of the invention.

The invention is claimed as follows:

1. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed; structure means locatedrearwardly of said key; at least one fixed contact element extendingfrom said structure means toward said key; a rigid switch arm fastenedto said key; a first movable contact element fastened to said structuremeans to extend into operable relaionship with said fixed contactelement and said switch arm; a pair of electrical conductors extendingtransverse- 1y of said key; and a second movable contact elementextending between said conductors in operable relationship with saidswitch arm, whereby depression of said key repositions said firstmovable contact element with respect to said fixed contact element whilesimultaneously repositioning said second movable contact element withrespect to said electrical conductors.

2. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed; structure means locatedrearwardly of said key; at least one fixed contact element extendingfrom said structure means toward said key; a rigid switch arm fastenedto said key, having one end overhanging said key and the opposite endcanted upwardly from said key; a first movable cont-act element fastenedto said structure means to extend into operable relationship with saidfixed contact element and said switch arm; a pair of electricalconductors extending transversely of said key; and a second movablecontact element having a straight end portion extending between saidconductors, and an offset mid-portion depending into operablerelationship with the canted end of said switch arm, whereby depressionof said key repositions said first movable contact element with respectto said fixed contact element while simultaneously repositioning saidsecond movable contact element with respect to said electricalconductors.

3. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed; structure means locatedrearwardly of said key; at least one fixed contact element extendingfrom said structure means toward said key; a rigid switch arm fastenedto said key, having one end overhanging said key and the opposite endcanted upwardly from said key; biasing means disposed between saidkeybed and the overhanging end of said switch arm; a first movablecontact element fastened to said structure means to extend into operablerelationship with said fixed contact element and said switch arm; a pairof electrical conductors extending transversely of said key; a secondmovable contact element having a straight end-portion extending betweensaid conductors, and an oifset mid-portion depending into operablerelationship with the canted end of said switch arm; and capacitor meanselectrically connected to said second movable contact element, wherebydepression of said key repositions said first movable contact elementwith respect to said fixed contact element while simultaneouslyrepositioning said second movable contact element with respect to saidelectrical conductors in order to permit discharge of said capacitormeans.

4. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed; structure means locatedrearwardly of said key; at least one fixed contact element extendingfrom said structure rneans toward said key; a rigid switch arm fastenedto said key, :having one end rearwardly overhanging said key and theopposite end canted upwardly and forwardly from said key; a firstmovable contact element fastened to said structure means to extend intooperable relationship with said fixed contact element and said switcharm; a pair of electrical conductors extending in vertically aligned,parallel relationship transversely of said key spaced thcreabove; and asecond movable contact element having a straight wire end-portionextending between said conductors, and an offset mid-portion dependinginto operable relationship with the canted end of said switch arm,whereby depression of said key repositions said first movable contactelement with respect to said fixed contact element while simultaneouslyrepositioning said second movable contact element with respect to saidelectrical conductors.

5. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed by balance rail means;structure means located rearwardly of said key; at least one L-shapedfixed contact element extending from said structure means toward saidkey; a rigid switch arm fastened to said key, having one end rearwardlyoverhanging said key and the opposite end canted upwardly and forwardlyfrom said key; biasing means, including a tension spring disposedbetween said keybed and said switch arm; a first movable, straight wirecontact element fastened to said structure means and received in a slotin an insulating tab secured to said switch arm to extend into operablerelationship with said fixed contact element; a pair of electricalconductors extending in vertically aligned parallel relationshiptransversely of said key spaced thcreabove; and a second movable contactelement having a straight wire end-portion extending between saidconductors, and an offset mid-portion depending into operablerelationship with the canted end of said switch arm, whereby depressionof said key repositions said first movable contact element with respectto said fixed contact element while simultaneously repositioning saidsecond movable contact element with respect to said electricalconductors.

6. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed by balance rail means;structure means located rearwardly of said key; a pair of L-shaped fixedcontact elements extending from said structure means toward said key; arigid switch arm fastened to said key, having one end rearwardlyoverhanging said key and the opposite end canted upwardly and forwardlyfrom said key; biasing means, including a tension spring disposedbetween said keybed and said switch arm; a first movable, straight wirecontact element fastened to said structure means and received in a slotin an insulating ta-b secured to said switch arm to extend into operablerelationship with said fixed contact elements; a pair of electricalconductors extending in vertically aligned, parallel relationshiptransversely of said key spaced thcreabove; a second J movable contactelement having a straight wire end-portion extending between saidconductors, and an offset midportion depending into operablerelationship with the canted end of said switch arm; and capacitor meanselectrically connected to said second movable contact element, wherebydepression of said key in opposition to said biasing means repositionssaid first movable contact element with respect to said fixed contactelements while simultaneously repositioning said second movable contactelement with respect to said electrical conductors in order to permitdischarge of said capacitor means.

7. A switch arrangement for electronic musical instruments comprising: akeybed; a key pivotally mounted to said keybed; structure means locatedrearwardly of said key; an L-shaped, fixed contact element extendingfrom said structure means toward said key; a rigid switch arm fastenedto said key; a first movable, straight wire contact element fastened tosaid structure means to extend into operable relationship with saidfiXed contact element t 6 V and said switch arm; a pair of electricalconductors extending transversely of said key; and a second movablecontact element extending between said conductors in operablerelationship with said switch arm, whereby depression of said keyrepositions said first movable contact element with respect to saidfixed contact element While simultaneously repositioning said secondmovable contact element with respect to said electrical conductors.

8. A switch arrangement according to claim 7 wherein said first movablecontact element is a straight, Whisker Wire contact element.

References Cited in the file of this patent UNITED STATES PATENTS2,587,458 Fritts Feb. 26, 1952 2,636,593 Larsen et a1 Mar. 3, 19532,846,916 Osborne et al Aug. 12, 1958 2,931,877 Henley Apr. 5, 19602,963,564 Cutler et a1 Dec. 6, 1960

1. A SWITCH ARRANGEMENT FOR ELECTRONIC MUSICAL INSTRUMENTS COMPRISING: AKEYBED; A KEY PIVOTALLY MOUNTED TO SAID KEYBED; STRUCTURE MEANS LOCATEDREARWARDLY OF SAID KEY; AT LEAST ONE FIXED CONTACT ELEMENT EXTENDINGFROM SAID STRUCTURE MEANS TOWARD SAID KEY; A RIGID SWITCH ARM FASTENEDTO SAID KEY; A FIRST MOVABLE CONTACT ELEMENT FASTENED TO SAID STRUCTUREMEANS TO EXTEND INTO OPERABLE RELATIONSHIP WITH SAID FIXED CONTACTELEMENT AND SAID SWITCH ARM; A PAIR OF ELECTRICAL CONDUCTORS EXTENDINGTRANSVERSELY OF SAID KEY; AND A SECOND MOVABLE CONTACT ELEMENT EXTENDINGBETWEEN SAID CONDUCTORS IN OPERABLE RELATIONSHIP WITH SAID SWITCH ARM,WHEREBY DEPRESSION OF SAID KEY REPOSITIONS SAID FIRST MOVABLE CONTACTELEMENT WITH RESPECT TO SAID FIXED CONTACT ELEMENT WHILE SIMULTANEOUSLYREPOSITIONING SAID SECOND MOVABLE CONTACT ELEMENT WITH RESPECT TO SAIDELECTRICAL CONDUCTORS.